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Chikara Nakamura

Publications and source records attributed to Chikara Nakamura.

5 recordsLinked to original sources
arXiv2021

On Choice of Hyper-parameter in Extreme Value Theory based on Machine Learning Techniques

Extreme value theory (EVT) is a statistical tool for analysis of extreme events. It has a strong theoretical background, however, we need to choose hyper-parameters to apply EVT. In recent studies of machine learning, techniques of choosing hyper-parameters have been well-studied. In this paper, we propose a new method of choosing hyper-parameters in EVT based on machine learning techniques. We also experiment our method to real-world data and show good usability of our method.

cs.LG↗
arXiv2018

Cutoff for lamplighter chains on fractals

We show that the total-variation mixing time of the lamplighter random walk on fractal graphs exhibit sharp cutoff when the underlying graph is transient (namely of spectral dimension greater than two). In contrast, we show that such cutoff can not occur for strongly recurrent underlying graphs (i.e. of spectral dimension less than two).

math.PR↗
arXiv2016

Lamplighter random walks on fractals

We consider on-diagonal heat kernel estimates and the laws of the iterated logarithms for a switch-walk-switch random walk on a lamplighter graph under the condition that the random walk on the underlying graph enjoys sub-Gaussian heat kernel estimates.

math.PR↗